Method of electrical distribution.



No. 717,467. I Patented Dec. 30, I902;

- J. s STONE.

METHOD OF ELECTRICAL DISTRIBUTION.

(Application filed Aug 4. 1902.) (No Model.) 2 Sheets-Sheet I.

WITNESSES. INVENTUR.

fiM. 7 24/44/- No. 7|7,467. Patented Dec. .30, I902.

- 'J. S. STONE.

METHOD OF ELECTRICAL DISTRIBUTION. (Application filed Aug. 4, 1902.]

(No Model.) 2 Sheets-Sheet 2.

I FT .15. 7'3 g 7733. I H C ea Fig-4- 17%! z W r as G I GI i5 MK g??- m:N'unms PH'KRS co, Puo'mufna. WASHINGTON 0. c

UNITED STATES ATENT @FFICE.

JOHN STONE STONE, OF CAMBRIDGE, MASSACHUSETTS.

MET-HOD OF ELECTRICAL DISTRIBUTION.

SPECIFICATION forming part of Letters Patent N 0. 717367, dated December30, 1902.

Application filed August 4, 1902. Serial No. 118,210. (No model.)

T0 on whom it may concern.-

Be it known that 1, JOHN STONE STONE, of Cambridge, in the county ofMiddlesex and State of Massachusetts, have invented a new and usefulMethod'of Electrical Distribution, of which the following is aspecification.

My improvement relates especially to a method of electrical distributionin which vibrating. currents are employed and it is desirable to useautomatic relays in the circuit. In relaying such a circuit in which thetransmitting-generator and the relay-generator develop currents of thesame frequency a practical difficulty arises in that the vibrationstransmitted from the signaling-station to the relay on being-impressedby the relay-generator upon the main line not only pass to thereceiving-station, but also establish the constant operation of therelay for an indefinite period, thus thereafter preventing intelligiblesignaling. Instead of being effective at the receiving-station only thevibrations thus become constant and serve not only to confuse theoperation of the receiving instrument, but also to render constant thetransmitting action of the relay. The relay therefore becomes what maybe termed a center of wasted energy in that it continually signals toitself instead of relaying intelligibly to the receiving-station. Thereason for this in the case supposed is that the relay-circuit containsmeans for generating a vibrating current of the same frequency as thatwhich impresses the line at the signaling-station. The current sogenerated impresses the main line, and hence not only signals to thereceiving instrument, but also continues to actuate the relay-armaturethrough its coils, which are in a branch from the main line. So long,therefore, as the relay-generator can operate it will react upon itselfthrough the relay-coils irrespective of the signals transmitted from thesignaling instrument and irrespective of the action of thetransmittingstation, and will thus render nugatory any attempt at thetransmitting-station to communicate intelligibly with thereceiving-station.

My improved method of distribution consists in causing the signals whichare to be transmitted to effect the transmission of similar signals bycurrents of different frequency which shall act upon a properly-attunedreceiver by which the signals shall be received. In a circuit containingtwo terminal stations this method may be carried out by apparatus ateach station comprising, in addition to proper receiving instruments,means for producing and impressing upon a main circuit vibratingcurrents of a given frequency, with the addition at some convenientpoint of a relay adapted to respond to the impressed vibrating current.The local circuit at the relay-station, however, should contain meansfor producing and impressing upon the line a vibrating current ofdifferent frequency, and the receiving means at each terminal stationshould be such as will respond only to the vibrating currentsoriginating in the local circuit of the relay. In such acase, while thesignals are originated at a given frequency of vibration and excite therelay-armature, which alone is capable of receiving them, the signals ofdifferent frequency impressed by the relay-generator have no effect uponthe relay-armature, but only cause a response in the receiving meanswhich is made resonant to the frequency of current developed by therelay-generator. It is evident that this method may be elaborated inVarious ways and that by its use a main line can be utilized for anumber of stations each having its own system, comprising a signalingand receiving means differently attuned and a relay the receiving memberof which is attuned to the transmitting means of thesystem, and thetransmitting member of which is attuned to the receiving means of thesystem, the several instruments of each system being differently attunedfor the instruments of every other system.

I have shown in the drawings in diagrammatic views several means bywhich my method may be carried out.

Figure 1 shows a two-station line; Fig. 2, a four-station line. Figs. 3,4, 5, 6, 7,and Sshow various means for associating the resonant circuitsof the relay with the main line which may be substituted for those shownin Figs. 1 and 2.

In each of the views, A is the main line.

In Fig. 1' I have shown two stations (numbered, respectively, 1 and 2)having between them a relay-station, (numbered 3.) The station 1comprises transmitting or signaling and receiving instruments. Thetransmitting instruments are primarily a key it and means for impressinga vibrating current on the line, such as an alternating generator g, thereceiving instrument being shown diagram matically as an electromagnet6. Each transmittinginstrnment and each receiving instrument isconnected with the main line A by means of a condenser c c and an inductancecoil r r. The station 2 is arranged in like manner, its key beinglettered 73, its generator 9 its receiving instrument 0 its condensers c0 and its ind uctance-coils r 1'. The relay-station comprises arelay-coil R connected with the main line A through a condenser c andinductance-coil 0- the other terminal of the relay-coil R beinggrounded. The local circuit of the relay (marked L) comprises anarmature a in the field of the relay R means for developing a vibratingcurrent-for example, an alternating generator 9 connected with one coilof a transformer 25 an inductance-coil r and a condenser The second coilof the transformer t is connected through a condenser andinductance-coil r with the line A, its other terminal being grounded.Vhen my method is carried out by means of such apparatus, the

generators g and g are capable of developing currents of the samefrequency, and each is effective to operate only the armature a of therelay-circuit; but the generator g at the relaystati'on developscurrents of a frequency different from the generators g and g and iscapable of operating the armatures of the receiving instruments 6 6 Thussuppose a signal to be sent from. station 1. The generator g of thatstation causes the operation of the circuit-closing armature a at therelay-station, but has no direct effect upon the receivinginstrument eat station 2, for the reason that the circuit in which that instrumentis included is made resonant to the frequency of the current developedby the relay-generator g and not to the frequency of the generator g.The closing of the armature 0. however, causes the effective operationof the generator 9 which, developing a current to the frequencyof whichthe circuit in which is the receiver e is attuned, causes the receiver 2to receive the signal Without, however, in any way affecting thecontinued and intelligible operation of the armature a at therelaystation.

In Fig. 2 there are added to stations 1, 2, and 3, as above described,two other stations 4 and 5, with their relay-station 6, the parts beinglettered in like manner, as in Fig. 1; but each element at each stationbeing distinguished by the number of its station, the condensers beinglettered c c c 0 o, c, and c and the ind uctance-coils r r 1- r 1", r,and T In this case the generators g and g are capable of developingcurrents of the same frequency as in the former case, and each iscapable of operating the armature a at relaystation 3, while thegenerator g develops a current of a different frequency capable ofoperating the armatures of the receiving instruments 6 6 The generatorsg g are each capable of developing currents of the same frequency, afrequency, however, different from that developed by any othergenerators in the circuit, and are capable of operating the armature a,and the generator 9 at the relay-station 6 is capable of developing acurrent of still a different frequency which operates the armatures ofthe receiving instruments e c In this case the generators at stations 1and 2 operate the armature a only, the generators at stations 4 and 5operate the armature a only, while the generators g and operate,respectively, the receiving instruments 6 e and c a. It is evident,therefore, that either station 1 or station 2 may be operated at thesame time that either station 4 or station 5 is being operated and thateach relay will pick up the signal intended forit and transmit it to thereceiver intended to receive it, as above described. My method may beextended in like manner to include a greater number of stations thanthose shown and described above.

I have shown in Figs. 3 to 8, inclusive, various ways of associating arelay with a circuit of the character described for the purpose ofcarrying out my method of distribution, each way having certainadvantages which will not only be apparent to those skilled in the art,but will indicate the breadth of the application of my invention. Inorder to prevent unnecessary repetition in the description of theseviews, I have lettered What I term the local circuit of the relayviz.,that circuit which contains the generator and the armaturewith theletter L, the parts in that circuit when necessary being lettered, as inFig. 1viz., the generator g the condenser c the inductance-coil r thearmature a and the transformer t and I have lettered the circuit of therelay-coil R. In Fig. 3 the relay-coil R is in a loop-circuit R of themain line A, which loop-circuit contains an inductance-coil r and acondenser 0 The local circuit L contains one element of the transformert the other element of which is in the loop IV of the main line A, whichloop also contains the inductance-coil r and condenser 0 In Fig. 4instead of making a direct connection with the main line A, I haveinserted in the main line A one element of the transformer i the otherelement of which is in the local circuit L, and

I have shown the relay-circuit R as containing also one element ofanother transformer 25 of similar character, the other element of whichbeing also in the main line A. In Fig. 5 the arrangement is similar,except that between the relay-circuit R and the main line A,I haveintroduced a weeding-out circuit W, comprising an element of each of twotransformers, one, the transformer T, the other element of which is inthe circuit R, the other,

the transformerT ,the otherelement of which is in the main lineA, and inthe same way the localcircuitL afiects the main line through aweeding-out circuit W, similar in all respects to the weeding-outcircuit W, but acted upon by the transformer li and acting through atransformer T upon the main line. In Fig. 6 there is a furthermodification in which the weeding-out circuits W and W form loops in themain line A, the local circuit being lettered L, as before, and a thirdweeding-out circuit W being effective to communicate the impulses bymeans of suitable transferences from the local circuit L to theweeding-out circuitW, looped into the main line. In Fig. 7 there isstill another modification, in which instead of weeding-out loops, asshown in Fig. 6, grounding branches G' and G are provided, each carryingone element of the transformers 25 T respectively, a condenser 0 0 aninductance-coil r r the relay-circuit R, also containing one element ofthe transformer and the local circuit L, also carrying one element i ofthe transformer, which acts upon the branch G through the weeding-outcircuit W. Still another modification is shown in Fig. 8, where therelay-circuit R is in a loop-circuit of the main line A, having a coil Aof small inductance as compared with the inductance-coil?" of therelay-circuit, the local circuit L being also a loop of the main line Aand having a coil A of small inductance compared with theinductance-coil W. In this modification the coils A A serve to directthe energy of the currentinto the local resonant circuit containing therelay. From this it will be seen that my method herein described may becarried out by means of any one of a number of combinations andmodifications, many of which, as well as many others, will suggestthemselves to one skilled in the art when it is understood that thepurpose of my invention is to provide a method of relaying by means ofresonant circuits which consists in causing the signals which aretransmitted by one or more generators transmitting waves of differentfrequencies each to its own relay, from which the signals areretransmitted by generators capable of transmitting waves of otherfrequencies to receivers of corresponding frequency.

I have described my method as carried out by placing such apparatus asneeds to be selective in its operation in resonant circuits attuned tothe frequency to which it is to respond; but I do not wish it to beunderstood that this is the only means by which my method of relayingmay be carried out, as its novelty depends upon the use of one frequencyfor transmitting and another frequency for receiving and not upon themeans employed for imparting the selectivity to the mechanism.

What I claim as my invention is 1. The method of relaying signalsreceived by a tuned receiver of an alternating-current telegraph systemwhich consists in causing such signals to effect the sending of similarsignals by currents of a different frequency.

2. The method of absorbing the energy of currents of one frequencytraversing a main line to the exclusion of the energy of currents ofother frequencies traversing said line, which consists in diverting theenergy of the current of said frequency by means of an inductance-coilincluded in said main line into a local resonant circuit containing atuning-coil of inductance very large compared to the inductance of saidcoil included in the main line.

In testimony whereof I hereunto set my name this 29th day of July, 1902.

JOHN STONE STONE.

Witnesses:

GEORGE O. G. CoALE, M. E. FLAHERTY.

